SALOME : impeller design

Salome : Free and Open source cad and meshing software. Today I tried using salome to model a impeller. The model was not an accurate design but an approximate to the actual one. Salome lacks a majot feature for blade designing i.e "loft". This was the only issue which I faced while creating the geometry.

Now let me explain you the steps in salome for making this design.

P.S. : The dimensions are in mm and other dimensions are just taken randomly.

Step 1.

In salome go to  " New Entities > 2D Sketch " and create a 2D image for the impeller as shown.

Step 2.

Click on the  " Reset Axis " to change the view of the sketch.

Create a face for the sketch using  " New Entity > Build > Face ".

Select the edges of the sketch and then click on Apply.

Step 3.

We need to revolve the face along an axis to complete the impeller design.

Go to " New Entity > Generation > Revolution ".

Click on the face and the axis along which we want to revolve and provide the input for revolution. In this case it is 360 deg.

Step 4.

Now we need to create the blades for the impeller.

Note that : The blades here are not having the perfectly aerofoil design shape as expected. The Salome seems to be lagging the lost function or may be I am not able to find it and hence its just an approximate design which I have come up with.

The thickness of the blade is 4mm and the top and bottom part of the blades are having a length of 58 mm and 80 mm.

To create the blade go to points and then create the points at the top surface of the impeller and at the bottom surface where the impeller blades cut the impeller.

Twist the bottom surface of the blade by and angle of 45 deg and having some curved surface.

STEP 5.

Similarly create a face for the blade and not extrude it along the Z axis.The blade has a thickness of 4 mm.

STEP 6.

To make multiple blades we need to create multiple copies of the blade. This can be done as follows :

Go to "Operation > Transformation > Multi-rotation"

Now create about 22 such copies of the blade with an angle of 25 deg in between each blade.

Now to make the geometry as a single model fuse the impeller and the blade using the fuse option. (" Operation > Boolean > Fuse ")

Save the mesh as impeller.msh (save it in ascii format)

This completes our geometry although not exact, but still an effort to create a impeller blade. I hope the loft option gets updated in the new release of Salome.( I am currently using Salome 7.2.0)

Meshing might take a while....so stay updated.. :)

Using Latex

For the time being please go through these spoken tutorials which are made by my Project Invigilator Prof. Kannan Modugalya. Simple 10 minutes tutorial will not only help you to learn latex but will help you learn it really quickly.

LINK : http://www.spoken-tutorial.org/tutorial-search/?foss=LaTeX&language=English

Plotting a variable against time in paraview 4.1.0

Paraview is really awesome and I bet once you start using it you would actually love it. Few things have changed in the new version of paraview and some I, myself had issues in dealing with some of the features. So my professor told me to get a plot of a scalar quantity v/s time and zoinks!!!..I gave a yes nod , but when I actually went and tried doing it I wasn't able to locate the option for plotting it. So after spending a quality 48 hours I realized it was a bit tricky and there was no good link/ forum / user manual available for doing it. So make life easier for beginners and paraview lovers and my friends these are the steps of creating a plot a graph with time.

STEP 1.

Open your OpenFOAM or any other format that you wish to open in Paraview.

STEP 2.

View your geometry along any direction you wish to.

STEP 3.

Now click if your geometry is 2D, you need not worry. But if it's 3D I would suggest to make the opacity of your geometry to 0.7/0.6 and and take a cut section at that location.


STEP 4.

After this now the real change comes into picture. In all the older versions of paraview we had Selection Display Inspector for selecting a location in the geometry, which is disabled in the latest version. In place of which a new option is provided just above the user interface window..which has a small icon named "SELECT POINTS ON". Click on this.

STEP 5.

Now place the point in your desired location and now select PlotSelectionoverTime.

STEP 6.

Click Apply and then wait for some time. For simple simulations it may be work quite fast and you will get a plot of various quantities v/s time. But for complex geometries it may take a while as it may consume more a greater chunk of your RAM.

STEP 7.

This end up the plotting . Now label your axis and use these graphs for your Reports. Happy plotting... :) !!!!

FOSS family just keeps growing...

It has been a fantastic journey with the FOSSEE (Free and Open Source Software for Science and Education ) team and it still continues to grow. Since I joined the team way back in 2011 and now when I see it today there is a lot of increase in the entropy of the whole project. With FOSS spreading like a wild fire in Indian Universities these days the addition of new FOSS tools has certainly bolstered the mission in a great way. From learing Scilab, Python to doing doing simulations using OpenFOAM to building a Inhouse Electrical software CAD tool, OR tools for optimization ,it really shows the efforts put up by every one.

I really wish the use of FOSS tools reaches every nooks and corners of India to save lot's of money that we invest on commercial tools and thus by investing the same money to develop the man power required to make FOSS more effective.

More information : http://fossee.in/  

3D bend pipe = Salome + OpenFOAM ( simpleFoam with temperature )

Posting this after a long break......

Simulation of a steady flow in a 3D pipe bend using Salome and OpenFOAM. Energy equation was added to the OpenFOAM solver Salome and a new solver named "simTempFoam" was developed. The geometry is a pipe with a diameter of 0.3 m and having a total length of 100 m and velocity of 1 m/s.

Pipe : Inlet, Outlet and wall boundary

The above figure Shows the geometry created in Salome v 7.2.0. The meshing was carried out in Salome itself and hexahedral mesh was used for the meshing.

Hexahedral mesh was generated using Salome with a total cell count of 60000

OpenFOAM was used for solving the flow through the bend. A steady state solver named "simTempFoam" was developed for with addition of energy equation. The solution converged in 300 iterations resulting in the following pressure, velocity and temperature contour plot.

Pressure contour

Velocity contour

Salome - Open Source CAD and Meshing Software

I recently started using Salome as a CAD and Meshing tool. Though initially I found it a bit tough to start up with but with practice I have found it much easier to work. The software was developed by a Finnish Institute in 1995 and since then has undergone many developments.
The software has some really good geometry building feature which are found even in commercial softwares. The concept of exploding the geometry into solid ,faces, wires has really caught my eye as that is something very unique about this software.
Once the CAD file is made it can be easily shifted to the Mesh Module. Now the only thing here is to be taken care of is the Meshing strategy to be used. User needs to understand what kind of a mesh is required for his/her geometry and accordingly choose the methods. Also the limit for the cell count here is 500000, I really don't understand the reason behind this as it sometimes the user requires to compromise on the mesh cell count ( some geometries require huge number of cells ). The Mesh file can be saved in  " .unv " format and can be used in OpenFOAM. There are a lot of other features which Salome offers which I would explore with time, but yes being open source this is a a real good software to look out for an save your money : ).

Salome site : http://www.salome-platform.org/

ESI-OpenCFD releases OpenFOAM® 2.2.1

ESI-OpenCFD has released the next version of OpenFOAM v2.2.1. It includes some new solvers and some more utility addition in heat transfer module. To Download and check more updates on the new version :

http://www.openfoam.org/version2.2.1/

OpenFOAM GPGPU computing

Found a dell blog showing the use of GPGPU with OpenFOAM

http://en.community.dell.com/techcenter/high-performance-computing/b/hpc_gpu_computing/archive/2012/09/06/accelerating-cfd-using-openfoam-with-gpus.aspx

OpenFOAM -2.2.0

OpenFOAM - 2.2.0 relised. To download and install openfoam and paraview visit the website : www.openfoam.org

You can also visit the link for audio video tutorial on installing openfoam and paraview and basic level tutorials :

www.spoken-tutorial.org

Tank Drianage using InterFoam VOF solver

Tank Dimensions (2m X 3m),outlet pipe dimensions (0.2m X 1m) . Solver used InterFOAM.

Flow over multiple cylinders in V-configration-OpenFOAM

Installing pyFoam for OPENFOAM

PyFoam is a scripting language for OpenFOAM.Being similar to python the script can be used to make changes in FOAM case directories.

Below given are the steps for imstalling PyFoam on your linux machines:

STEP 1)

Downaload the latest version of "PyFoam" from the link given below:

http://openfoamwiki.net/index.php/Contrib_PyFoam

STEP 2 )

It will be a tar file. Untar the tar file in the folder of your choice

STEP 3)

Open the command terminal and go to the folder in which you have untared the pyFoam file.

STEP 4)

Using Synaptic Package manager install these two library files which are needed for pyFoam

libboost -dev

libboost -doc

STEP 5 )

In pyfoam folder you will see a set up file named "setup.py"

In the terminal window type the command :

python setup.py install

STEP 6 )

You are done with installation.

To check your installation in the terminal type "python"

Now type :

import PyFoam

import PyFoam.FoamInformation

print PyFoam.FoamInstallation.foamTutorials()

This command should produce a output showing the openfoam tutorials directory.

Moving wall ...@ OpenFOAM

ThermoPedia

http://www.thermopedia.com/content/674/?tid=104&sn=1410

A complete guide to understand basics of Thermodynamics,Fluid Mechanics,Heat transfer.A very useful page for Under Grads (UG).

GRID PRO-Ultimate tool for meshing

GridPro is an automatic, object-oriented, multiblock grid generator.
It provides users with a highly efficient, interactive capability to build topology, edit surfaces, set CFD boundary conditions, view grids and launch the grid generator.
Users interact with GridPro through the Az-Manager, an easy-to-use, dynamic 3D environment that combines a powerful scripting language with a user-friendly GUI front end. Automated processes minimize the amount of manual manipulation required to generate a grid, reducing errors in grid specification.
GridPro automatically creates templates of your grids to permit fast optimization to meet specific criteria.
To ensure that the highest quality grids are generated, the software engine incorporates a unique algorithm using advanced mathematical techniques. The algorithm optimizes each grid so that every element is smooth and orthogonal throughout the volumetric region under consideration

For more information on gridpro visit: http://www.gridpro.com

OpenFOAM Spoken Tutorial

Tutorials for Self Learning OpenFOAM have been made online.People interested in learning OpenFOAM can go through these tutorials and in case of any doubts they can post their comments here on the blog or can send me an email.It would surely be a great learning experience for everyone,so lets start with the open source CFD world.

Link for the tutorial:

www.spoken-tutorial.org/New

Rotating circular cylinder

Simulation of Rotating Circular cylinder in OpenFOAM

Boundary conditions:

Re=70

omega=2 rad/s

velocity = 0.7 m/s

7th OpenFOAM® Workshop

The 7th OpenFOAM® Workshop will be held in Darmstadt (next to Frankfurt, Germany) from June 25-28, 2012 - hosted by the Center of Smart Interfaces (CSI) and the Graduate School of Computational Engineering (GSCE) of the Technische Universität Darmstadt


http://www.openfoamworkshop.org/2012/OFW7.html

Simulation for flow over a circular cylinder using OpenFOAM

  OpenFOAM : Flow over a circular Cylinder

OpenFOAM 2.1.1 release

The latest version of OpenFOAM 2.1.1 was released on 31/5/2012.Bugs are removed and a lot of new features have been implemented after the 2.1.0 release.
To download OpenFOAM 2.1.1 visit the openfoam website on this url:
http://www.openfoam.org/download/

You can also download openfoam from synaptic package manager by simply typing in the terminal OpenFOAM.

P.S: In case it doesn't show up try fixing the repository by adding it manually in  synaptic  package manager > settings > repository > othersoftware and add the required openfoam repository